Animal Logic Goes On the Hop for 'Peter Rabbit'

Animal Logic was awarded the chance to design, build and animate the cast of creatures in the film 'Peter Rabbit', based on one of the best-known and most enduring children's story books ever written, 'The Tale of Peter Rabbit'. The creatures they created, and many props, were composited into the film's live action photography in post production. Digital Media World talked to VFX supervisor Will Reichelt and animation supervisor Simon Pickard about the team's work at Animal Logic.

About one year ahead of principle photography in early 2016, the animation and VFX teams at Animal Logic started character development with a focus on the original 'Peter Rabbit' books that were written and illustrated with drawings and water colours by Beatrix Potter in the 1890s.

The director Will Gluck's vision called for entirely photoreal rabbits and animal friends, tangibly inhabiting the plates and realistically detailed in every way. In the early stages of character design and development, marrying the original illustrations with realism and photoreal rendering was the main challenge for the artists on the animation and VFX teams at Animal Logic.

How much should these creatures truly look and feel like real rabbits? How closely should they match the details visible in Potter's illustrations? As sketches and watercolours, her artwork has a realistic foundation but leaves out many finer details of fur, fabric and the facial requirements for speech, which meant the team needed to fill in various 'blanks' when defining the models.

Performance Driven

Will Reichelt said, “The rabbits’ anatomies were a unique blend of a real rabbit with bespoke adjustments to limb and body proportions that would allow them to stand on two legs and walk, as well as go down on four legs and run. In the books, the characters spend a lot of time standing up on two legs, but the two-leg animation tests often felt wrong and didn't match the director's ideas about the rabbits' moves and personalities. The final performances alternated between two and four legs, depending on the action, the story, how fast they had to move and so on.

“We went through an extensive testing process to determine how this would work in the animation rigs. We needed to make something that would evoke a real rabbit and work technically with the combination of their movements and the clothing, but would also look appealing and be able to perform as they needed to as anthropomorphic characters in the film.”

Simon Pickard led Animal Logic's animation department, at first a small group of two or three artists in pre-production and production that eventually swelled to six teams of about 12 artists each during post. Like the models, the animation started out with an emphasis on realism. The artists began by layering in realistic rabbit behaviours, but they also realised that if the audience were going to engage with the cast, the creatures also needed to reflect the voice actors' timing and performance style. So, the animators needed to loosen up the motion and make it as performance-driven as possible.

During this stage the animators and riggers regularly worked back and forth with Will Reichelt's department as they finalised the models and character effects, all working on a modelling and animation pipeline based on Maya. The story was still evolving as well, and whenever the motion changed to accommodate the story, the fur, cloth and other simulations had to be updated. Between them, the two departments worked hand-in-glove to produce many iterations between realism and the Potter illustrations.

Talking the Talk

Talking was a particular challenge when trying to reconcile real rabbits' incessantly twitching noses with effective performances. Like the full-body motion, their facial range of motion remained on a sliding scale as the story progressed and the animators gained a clearer idea of what actions the rabbits needed to perform.

Simon said, “The development of the facial rig needed to be fluid while we locked down the style of facial animation. Early on, we headed towards a realistic, restrained, bunny-like performance. What we found was that rabbits are very twitchy and never stop moving – especially their noses. After a few tests we realised that this is actually pretty tiring to watch as a viewer. During this development we also tested actual lines from the script, trying to find a good balance between a realistic rabbit and a face you could believe that each particular actor's voice was coming from.

“As the characters settled we knew these ranges needed to expand in some areas, especially around the eye and brow, where rabbits are quite muted, and then we reduced our nose twitches, reserving them more for character beats.

“Of course, while all this discovery was happening, the other departments linked with animation needed to provide updates. Modelling would supply shapes with increased ranges as required, which then fed back into the facial rig and back out to animation. We would then redo the tests and re-deliver back to the director. This loop kept going until everyone was happy that we had a face expressive enough to capture the actors' performances, and animation ranges we needed for the show.”

Rabbit Personalities

Meanwhile, they concentrated on finding the personalty of each character. Peter's plump, affable best friend Benjamin, for example, needed to be a bit slow on his feet. But the first motion tests for him were so clumsy that he looked slightly stupid. “We had to consider how well people would relate to the characters, and let each animator bring something of his or her own experience into the performances,” Simon said.

Fur was a key feature – rabbits just don't seem like rabbits without it. The fur for Peter and his friends is thick and tactile-looking enough to change the overall impression of a character's motion. Both the rig and the animation needed to compensate for it. It was created with Animal Logic's own fur simulation and grooming software Alfro and their proprietary renderer Glimpse.

Will said, “We started developing Glimpse a few years ago on the Lego Movie and it has since taken over from RenderMan as our sole production renderer. Alfro employs guide hairs to control the groom of a creature's fur, and was used for the 5 to 8 million hairs required for each rabbit. It also controls the simulations that prevent the hairs in dense fur from constantly intersecting each other and interfering with the appearance of the effect.”

As the team was busy producing character effects for about 1,100 shots in the film, automation of certain effects was an attractive option. Because the rabbits were always wearing clothes, the director was concerned about interaction between the cloth and fur. Instead of having to set up interactive simulations for every shot, Will's team successfully automated them in a process that output a basic render to show the director at the same time.

Pre-production

All of the character development and work on animation style was essential to begin working on as early as possible but ultimately, at every moment, the animated performances had to be closely aligned with the live action and invisibly integrated into the physical sets. First, the story calls for close personal contact between the live action and CG characters in sequences ranging from comical to touching. Therefore, the animation and FX teams had to be fully aware of and involved in what was happening on set throughout principle photography, which took place in early 2017, and some time before any compositing or any post production tasks got underway.

Will worked on set throughout the shoot, advising the production and supervising the camera work if necessary. Simon or another of the animation directors usually worked with him to help block out the action and timing. “One very helpful technique the production used for a couple of weeks in pre-production was called 'Bunny Troupe'”, Will said. “It involved blocking out and filming shots on the practical garden set, which was still under construction at the time, using stand-ins and people holding foam-board representations of the rabbits on sticks who would manoeuvre them around to represent their staging and action.

“It worked essentially like live-action pre-vis - the footage was edited together and adjusted to help the director determine the shot list for the shoot. Doing it this way, rather than with traditional digital pre-vis, worked out better for the Director as it gave him more immediate feedback about whether he had actually planned for what he needed or not. This pre-vis was then used by the 1st AD, DP and others on set as a guide to figure out what they needed to do, exactly like normal pre-vis.”

Integration of the rabbits and creatures had to be faultless, and during production, the director wanted to be able to monitor the looks and the effects of light and physical contact on the rabbits within the shots as production proceeded. He found Animal Logic's Renderboys tool extremely useful for doing this. Also an example of automation, Renderboys is a rendering process that is automatically carried out whenever an artist checks in their animation work at the studio. Due to its lower quality settings, it can produce very fast renders but its output is still capable of indicating how their image-based lighting, shadows, fur and cloth simulations and other looks and effects will appear in shots within a just a few hours of the shoot or overnight, instead of days.

Absent Friends

To both fulfil the director's vision and make the work more straightforward for Animal Logic's teams in the studios, the sets were the site of some key activities apart from filming the actors. The use of stuffies on set, for example, was critical in order to draw more convincing performances from the actors, because the rabbits physically engage with the live action characters so closely in so many sequences. These better performances meant that, in turn, the animators had more realistic moves to animate against in post. Each stuffie was weighted and designed to match the body of a real rabbit, and the actors were trained how to handle them as if they were alive.

Will said, “The human to CG interactions were among the hardest challenges. We had a sequence in the conservatory, for instance, showing a comical skirmish between Peter and Macgregor in which getting that live-action-to-CG connection was critical to the humour, but almost impossible to define until we finally hit upon it by trial and error.

“When Macgregor grabs Peter and glares at him, face to face, Peter kicks and struggles with his powerful hind legs, just as a real rabbit would do. But we couldn't have the audience worrying about Peter or MacGregor actually hurting each other. We wanted to bring out the humour of their relationship instead by choreographing the beats and introducing the right deformations and reactions in Peter's model and performance. As a result, once we had an understanding of the limits and possibilities of the models and animation, and started blocking out the action on set, Animal Logic had some influence on the story at certain points.”

From Set to Studio

While the shoot proceeded Will sometimes relayed takes back to the studio to show Simon. Together they would quickly assess the shots as a foundation for animation. Simon said, “On set we had a live playback system showing in real-time what the cameras were shooting. I could see the shot as it was being filmed and was also connected to Will via headset audio so we could speak instantly while he was on set with the actors and director.

“As shots were filmed I could then give Will an instant yes or no call based on if I thought we'd be covered in animation or if there were framing, timing or interaction problems. It was a great system that allowed us to catch potential issues as we went, while everyone – production crew with the cameras, the talent and the staff from Animal Logic – was still on set.”

An important physical parameter in the plates for the animators to work with and conform to was rabbit speed. For an animator, speed suggests other characteristics like weight, emotion and strength. On set, the supervisors could advise the production about the feasibility of getting a rabbit to move between one point in the frame and another, and accomplish certain moves, in a given amount of time, but in the end they had to be flexible. “We often had to cheat a little, because we had to work with the footage. The ideal was to allow consistency of performance for each character while fitting with the live action as shot.

Catching the Light

Accurately capturing the lighting conditions as HDR images from the set is important for photoreal work, and for 'Peter Rabbit' it was essential to integrate the CG creatures invisibly into the plates. Will and the team tried a new technique to improve on the traditional method of using a DSLR to capture a series of shots with manually bracketed exposures, which often produces inconsistent results and is prone to human error. Furthermore, shots for this film had to be captured very close to the ground, where you'd expect real rabbits to be running around, and the production also wanted to automate the processing of onset data for speed and accuracy.

To achieve these goals, they hired a small IndieCAM that was specially adapted into a 4K VR camera and recorded images through two fisheye lenses, each with a wide enough angle to – between the two of them – capture the full 3D scene. Bespoke software was written that would capture consistent, perfectly bracketed shots, and was remotely controllable via a tablet to initiate the recording. The result was not only much quicker and less disruptive on set, but also yielded data from more positions across the scene

A Rabbits' World

Animal Logic also worked with the production designer and costume designer early on as well as with the special FX team. Making sure everyone agreed on the significance and design of key story props and sets like the vegetable garden, the vegetables, the garden gate, Peter's blue coat and so on was important to making the sequences work. The production actually grew a real vegetable patch and, depending on the action, the garden was populated with digital, real and plastic prop produce.

Meanwhile the director was very keen to have as much motion recorded in camera as possible. Consequently, during the garden chase scenes, the special FX team members would crouch off-camera and tug branches aside on strings to prepare for the digital rabbits as they rushed past to avoid MacGregor, and did the same with Peter's coat as it gets caught on the bushes.

Director Will Gluck's vision of the rabbits' world was much like the design of their bodies - a blend of a real rabbit natural history, and bespoke adjustments to their environment to support the needs of the story. Their burrow was an example of this. The production did consider following the books' illustrations of the rabbits at home in a cottage, making tea and so on. But the director steered away from that notion and had Animal Logic design and build a 3D version of a burrow that is very similar to a real rabbit burrow, opened up and lit inside so that they could animate the rabbits and include a 3D camera.

Shopping in Ambleside

'Peter Rabbit' was filmed in or close to Sydney, Australia. Photography included a number of location shoots that needed to evoke the English countryside, calling on Animal Logic's team to enhance the environments in post. One of their most challenging tasks of this kind was creating a country ironmongers shop from photography shot at two separate locations.

The live action interior shots were shot in a real hardware store in Sydney. Will said, “For the exterior, we searched the streets of the English town of Ambleside on Google Earth, and located a similarly-sized space along the street where the hardware store could conceivably fit. This space was in fact a car park. We created a pre-vis using the footage we’d shot in Sydney, and showing the views we would need to capture for the backgrounds.”

However, when they arrived in Ambleside, they realised that local restrictions affecting the street space they had chosen meant they wouldn't be able to get the necessary angles. Fortunately, as they walked back down the street they managed to find a much better space – a street turnoff that created an almost-perfect sized gap between the shops for the hardware store to fit, and a much more pleasing visual outlook.

“We had some locked off shots where we could just line up the camera information and shoot the plate to drop into the background, but we also had shots with moving cameras and no access to motion-control. So we LIDAR-scanned the street, did extensive photography of the buildings, and shot plates with moving extras from median positions along the camera moves so we could re-project the building footage onto the geometry, roto the extras and put them back onto cards in 3D space and then track everything back into the original camera move," Will said.

“Because the space in Ambleside was shorter in width than the real hardware store, we had to do some additional paint work in some shots to extend the buildings, which making the LIDAR scan and photography even more important. The lighting conditions between the two sets of plates were quite similar but oddly, when we shot in Sydney we had anticipated that it would be raining when we filmed in England. We had actually done a full wet down of the street. But when we shot in Ambleside it was a beautiful, bright sunny day! The locals laughed at us as we wet down their street to make it match.” www.animallogic.com